function changelang(sCurLang,sLang) 
{
	var sUrl=document.location.href;
	sCurLang='lang='+sCurLang;
	var iPos=sUrl.indexOf(sCurLang);
	if (iPos<0) {
		iPos=sUrl.indexOf('?');
		if (iPos<0)	
		  sUrl=sUrl+'?lang='+sLang; 
		else 
		  sUrl=sUrl+'&lang='+sLang;
	} 
	else 
	  sUrl=sUrl.substring(0,iPos)+'lang='+sLang+sUrl.substring(iPos+sCurLang.length);
    
	document.location.href = sUrl;
}